Internet protocol (IP) address sharing and platform dynamic host configuration protocol (DHCP) mediator

#In a computer environment where two or more computers are connected in a Local Area Network (LAN) arrangement, the computers may operate in accordance with a Dynamic Host Configuration Protocol (DHCP). A typical computer includes a host computer with an operating system (OS) stack and driver, and a LAN controller to communicate to other computers on the LAN. Communication is controlled by the OS stack and driver. The host computer stack and driver maintain the Internet Protocol (IP) address. Typically the LAN controller is not aware of the IP address, but rather the LAN controller may be aware of and looks for the Medium Access Control (MAC) address. The LAN controller may include an integrated Central Processing Unit (CPU) manageability entity that communicates to the network through the same LAN connection as the host computer. The manageability entity is addressable because it must be accessible from other network computers outside of the host computer. In one setup, if the manageability entity has its own IP address, it must have its own MAC address. In another setup, the manageability entity may use the same MAC address as the host computer where it shares the IP address of the host computer (e.g., in a DHCP environment). In a non-DHCP environment, with the same MAC address, the host computer and the manageability entity each can have its own IP address. In a DHCP enabled environment a network device, such as a LAN controller, may synchronize its usage of IP addresses with that used by a host OS. In other words, the network device may use the same IP address when the host OS is up and running and retain a DHCP address when the host OS is inoperable or malfunctioning. Some network computer applications provide two or more computers that share a LAN interface and are expected to share one IP address. The computers may have to share one IP address network IP address allocation may be limited (e.g., IPv4) and because it is likely that the computers may be accessed using one IP address or using the same network name as though they were a single computer.

#In DHCP applications, the two or more computers may work together or separately, so that when one computer is shut down, hanged, or in standby, the other one is still functional and may be accessed over a network. If the IP address is leased from the network using a standard DHCP, then only one of the two or more computers may negotiate for the single IP address and run the protocol against the DHCP server. If the computer goes into shutdown mode, is hanged or becomes standby, then the other computer maintains the lease on behalf of both of them.

#When a DHCP server allocates IP addresses based on different DHCP parameter options that are provided by a DHCP client computer, the computers that share the same IP address lease must appear to the DHCP server as a single entity. An example of such system is a Network Interface Chip (NIC) that serves a host OS with an OS driver that includes an embedded manageability computer to operate and communicate to the LAN while the host system is running as well as when the host computer and its OS are in shutdown, hanged or standby mode, or is shutdown. The embedded manageability computer must be accessed regardless of the state of the host OS, so that it can be reached even if the host OS is not capable of extending the DHCP lease.

#FIG. 1 illustrates one embodiment of a system 100

#FIG. 2 illustrates one embodiment of a block diagram of module 200.

#FIG. 3 illustrates one embodiment of a system 590.

#FIG. 1 illustrates one embodiment of a system 100. FIG. 1 illustrates a block diagram of a system 100. System 100 may comprise a communication system having multiple nodes. A node generally may comprise any physical or logical entity for communicating information in system 100 and may be implemented as hardware, software, or any combination thereof, as desired for a given set of design parameters or performance constraints. Although FIG. 1 may show a limited number of nodes by way of example, it can be appreciated that more or less nodes may be employed for a given implementation. The embodiments are not limited in this context.

#A node may comprise any physical or logical entity having a unique address in system 100. The unique address may comprise, for example, a network address such as an IP address, a device address such as a MAC address, and so forth. The embodiments are not limited in this context.

#The nodes of system 100 may comprise or form part of a network 150, such as a LAN, a Metropolitan Area Network (MAN), a Wide Area Network (WAN), a Wireless LAN (WLAN), an Internet network, a World Wide Web network, a telephony network (e.g., analog, digital, wired, wireless, Public Switched Telephone Network (PSTN), Integrated Signal Digital Network (ISDN), or Digital Subscriber Line (xDSL)), a radio network, a television network, a cable network, a satellite network, and/or any other wired or wireless communications network configured to carry data. Network 150 may include one or more elements, such as, for example, intermediate nodes, proxy servers, firewalls, routers, switches, hubs, adapters, sockets, and wired or wireless data pathways, configured to direct and/or deliver data to other networks. The embodiments are not limited in this context.